So, what will start with on Monday is doing the most simple example of methane using these Lewis structure rules.

因此，下周一上课,我们会先以最简单的例子--甲烷开始,使用这些路易斯结构的规则。

麻省理工公开课 - 化学原理课程节选

I mean that, that's an endemic problem. But, you know, I mean the rules are actually pretty simple.

那是一个地域性的问题。但是，这其实是非常简单的规则。

经常犯的失误 - SpeakingMax英语口语达人